First, make sure your computer is fully booted and try again. If that doesn't work, then try holding the open button. If that doesn't work, go to (My) Computer, right click on the drive and choose Eject. If that still doesn't work, look for a tiny hole under the drive tray. If there is one, take a paperclip, fold it over, and push it (hard) into that hole. The tray will open. If there's no hole... you're out of luck. Maybe install new drivers.